Dual mass cooling precision system

ABSTRACT

Devices, systems, and methods are disclosed for cooling using both air and/or liquid cooling sub circuits. A vapor compression cooling system having both an air and liquid cooling sub circuit designed to service high sensible process heat loads that cannot be solely cooled by either liquid or air is provided.

BACKGROUND

A conventional cooling system for a high sensible process heat loadremoves heat from the working space through convective heat transferthrough the air. The air carries the heat from the process heat load tothe heat exchanger (evaporator) where heat energy is transferred into avolatile refrigerant that in turn absorbs the heat energy though a twophase process that involves a change from a sub-cooled liquid state to asuper-heated vapor state. While in this gaseous state a compressorincreases both the temperature and pressure of the gas so as to createthe higher temperatures needed to create the differential between thegas temperature and that of the heat removal medium (air, water, glycol,or other) that is required to transfer heat to the ambient environment.Since this heat transfer is dependent on the mass flow rate of the ofthe heat transfer medium (as well as the specific heat capacity atconstant pressure and the temperature differential) a liquid with itshigher specific mass may be needed to remove heat in situations wherethe existing heat flux exceeds the capability of air alone to remove theheat energy. In process cooling spaces where this higher heat fluxoccurs and 100% liquid cooling is not practical, a device and/or systemthat can simultaneously provide both cooling fluids, air and water, isneeded.

There accordingly remains a need for devices, systems, and methods thatprovide improved cooling other than solely liquid cooling.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings provide visual representations which will beused to more fully describe various representative embodiments and canbe used by those skilled in the art to better understand therepresentative embodiments disclosed and their inherent advantages. Thedrawings are not necessarily to scale, emphasis instead being placedupon illustrating the principles of the devices, systems, and methodsdescribed herein. In these drawings, like reference numerals mayidentify corresponding elements.

FIG. 1 illustrates a block diagram of a vapor compression cooling systemhaving both air and liquid cooling sub circuits, in accordance withrepresentative embodiments.

FIG. 2 illustrates a diagram with detail of a combined air and watercooling evaporator, in accordance with representative embodiments.

FIG. 3 illustrates an example coaxial tube, in accordance with variousembodiments.

FIG. 4 illustrates a block diagram of a vapor compression cooling systemhaving both air and liquid cooling sub circuits, and showing use of thesame to provide cooled liquid and air to servers, in accordance withrepresentative embodiments

FIG. 5 illustrates example construction of the dual air and liquidevaporator, in accordance with various embodiments.

FIGS. 6 and 7 illustrate examples in which the dual air and liquidevaporator is housed in a micro data center, in accordance withrepresentative embodiments.

FIG. 8 illustrates a methodology for simultaneously providing air andfluid cooling by a dual air and liquid evaporator, in accordance withvarious embodiments.

FIG. 9 is a block diagram that illustrates a process of dual air andwater cooling within the system, in accordance with various embodiments.

DETAILED DESCRIPTION

The various methods, systems, apparatus, and devices described hereingenerally provide for the cooling of loads using a combination of airand liquid cooling sub circuits. A vapor compression cooling systemhaving both an air and liquid cooling sub circuit designed to servicehigh sensible process heat loads that cannot be solely cooled by eitherliquid or air. This requirement is driven by the increased wattdensities experienced in many process cooling environments that exceedthe ability of air to remove all the heat but do require some air toaugment the liquid cooling capabilities due to space geometry and/or theinability to get fluid to all components that need to be cooled. Thesystem is distinguished by a combination air and liquid coolingevaporator, also referred to as a dual air and liquid evaporator.

While this invention is susceptible of embodiment in many differentforms, there is shown in the drawings and will herein be described indetail specific embodiments, with the understanding that the presentdisclosure is to be considered as an example of the principles of theinvention and not intended to limit the invention to the specificembodiments shown and described. In the description below, likereference numerals may be used to describe the same, similar orcorresponding parts in the several views of the drawings.

In this document, relational terms such as first and second, top andbottom, and the like may be used solely to distinguish one entity oraction from another entity or action without necessarily requiring orimplying any actual such relationship or order between such entities oractions. The terms “comprises,” “comprising,” “includes,” “including,”“has,” “having,” or any other variations thereof, are intended to covera non-exclusive inclusion, such that a process, method, article, orapparatus that comprises a list of elements does not include only thoseelements but may include other elements not expressly listed or inherentto such process, method, article, or apparatus. An element preceded by“comprises . . . a” does not, without more constraints, preclude theexistence of additional identical elements in the process, method,article, or apparatus that comprises the element.

Reference throughout this document to “one embodiment,” “certainembodiments,” “an embodiment,” “implementation(s),” “aspect(s),” orsimilar terms means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment of the present invention. Thus, theappearances of such phrases or in various places throughout thisspecification are not necessarily all referring to the same embodiment.Furthermore, the particular features, structures, or characteristics maybe combined in any suitable manner in one or more embodiments withoutlimitation.

The term “or” as used herein is to be interpreted as an inclusive ormeaning any one or any combination. Therefore, “A, B or C” means “any ofthe following: A; B; C; A and B; A and C; B and C; A, B and C.” Anexception to this definition will occur only when a combination ofelements, functions, steps or acts are in some way inherently mutuallyexclusive. Also, grammatical conjunctions are intended to express anyand all disjunctive and conjunctive combinations of conjoined clauses,sentences, words, and the like, unless otherwise stated or clear fromthe context. Thus, the term “or” should generally be understood to mean“and/or” and so forth.

All documents mentioned herein are hereby incorporated by reference intheir entirety. References to items in the singular should be understoodto include items in the plural, and vice versa, unless explicitly statedotherwise or clear from the text.

Recitation of ranges of values herein are not intended to be limiting,referring instead individually to any and all values falling within therange, unless otherwise indicated, and each separate value within such arange is incorporated into the specification as if it were individuallyrecited herein. The words “about,” “approximately,” “substantially,” orthe like, when accompanying a numerical value, are to be construed asindicating a deviation as would be appreciated by one of ordinary skillin the art to operate satisfactorily for an intended purpose. Ranges ofvalues and/or numeric values are provided herein as examples only, anddo not constitute a limitation on the scope of the describedembodiments. The use of any and all examples, or exemplary language(“e.g.,” “such as,” or the like) provided herein, is intended merely tobetter illuminate the embodiments and does not pose a limitation on thescope of the embodiments. No language in the specification should beconstrued as indicating any unclaimed element as essential to thepractice of the embodiments.

For simplicity and clarity of illustration, reference numerals may berepeated among the figures to indicate corresponding or analogouselements. Numerous details are set forth to provide an understanding ofthe embodiments described herein. The embodiments may be practicedwithout these details. In other instances, well-known methods,procedures, and components have not been described in detail to avoidobscuring the embodiments described. The description is not to beconsidered as limited to the scope of the embodiments described herein.

In the following description, it is understood that terms such as“first,” “second,” “top,” “bottom,” “up,” “down,” “above,” “below,” andthe like, are words of convenience and are not to be construed aslimiting terms. Also, the terms apparatus and device may be usedinterchangeably in this text.

In general, the devices, systems, and methods described herein mayprovide vapor compression to simultaneously provide air and liquidcooling specifically for high sensible process cooling loads.

Although the devices, systems, and methods described herein mayemphasize the simultaneous use of air and liquid cooling, and inparticular water cooling, the use of other types of liquid cooling mayalso or instead be made possible through the devices, systems, andmethods described herein including the use of water, glycol, and thelike.

Therefore, in accordance with the various embodiments described herein,the disclosure provides a vapor compression system capable ofsimultaneously providing air and liquid cooling for high sensibleprocess cooling loads. The disclosure in certain embodiments provides acombination water cooler (chiller), air cooler (evaporator),compressor(s), parallel electronic metering devices, liquid pumps,condenser(s), and controls. The system cools those portions of the heatload that cannot be reached by the liquid cooling while simultaneouslyproviding chilled water for liquid cooling process (direct to chip,emersion bath, etc.). It is important to note that the air and watercooling evaporator is an integrated unit that is serviced by a singlerefrigerant flow path and is housed in a common casing, in accordancewith certain disclosed embodiments.

Description of Device and System Operation

In accordance with embodiments described herein, a vapor compressionsystem, and, more particularly one vapor compression system, is operableto simultaneously provide air and liquid cooling for high sensibleprocess cooling loads. The vapor compression system has a combinationwater cooler (chiller), air cooler (evaporator), compressor(s), parallelelectronic metering devices, liquid pumps, condenser(s), and controls.The system cools those portions of the heat load that cannot be reachedby the liquid cooling while simultaneously providing chilled water forliquid cooling process (direct to chip, emersion bath, etc.). The airand water cooling evaporator may be an integrated unit that is servicedby a single refrigerant flow path and is housed in a common casing inaccordance with certain embodiments.

The dual air and liquid evaporator is operable to simultaneously provideprocess cooling liquid, such as water, a glycol mixture, a solution orother fluid, and cooled air to equipment such as liquid cooled computerservers, magnetic resonance imaging machines, industrial machines, andother devices that require both air and water cooling. The term water isused herein but the fluid could be a solution, as well as a glycolmixture, and the terms water and liquid may be used interchangeably. Aunique characteristic in accordance with the various embodimentspresented herein is the combined air and water evaporator, which mayalso be referred to as a dual air and water evaporator, dual air andwater evaporator coil, dual evaporator, evaporator coil, or the like,that may be comprised of copper tubing with aluminum or copper fins, aswell as the control algorithms employed by a controller thatsimultaneously control the cooling of water and air.

As described herein and as illustrated by the system block diagrams ofFIGS. 1 and 4, the system may have the following elements, in which thereference numbers correspond to those shown in the drawing:

-   1. Compressor or compressors, either fixed speed, digital, or    variable, single or tandem, scroll or reciprocating-   2. Refrigerant-   3. Condenser (may be air, water, glycol or other medium cooled with    appropriate head pressure controls)-   4. Flow regulating valve-   5. Refrigerant receiver-   6. Refrigerant drier/strainer-   7. Sight glass-   8. Electronic expansion valve-   9. Electronic expansion valve-   10. Dual air and water cooling evaporator/evaporator coil-   11. Air cooling section of dual evaporator-   12. Pressure transducer/sensor-   13. Liquid cooling section of dual evaporator-   14. Temperature sensor-   15. Temperature sensor, supply line-   16. Primary pump-   17. Shut-off valves-   18. To liquid cooling device(s)/system(s)-   19. From liquid cooling device(s)/system(s)-   20. Standby pump-   21. Strainer-   22. Temperature sensor-   23. Electronic evaporator pressure regulator valve (EEPR)/freeze    protection value-   24. Evaporator fan(s)-   25. Liquid cooled server rack/micro data center-   26. Pressure transducer/sensor-   27. Temperature sensor-   28. Remote air temperature sensor-   29. Programmable logic controller (PLC) with special control    algorithms-   30. Coaxial cable-   31. Outer tube-   32. Inner tube

As illustrated by the system block diagram of FIG. 1, during operationof this system return air and supply water temperatures are measured andthese values are communicated to the PLC 29. When the temperatures ofeither of these values is above the individual set point the compressorwill turn on to provide refrigerant flow to the air cooling evaporatorcoil, the liquid cooling chiller evaporator, or both. In systemscomprising two or more compressors the additional compressors will turnon at set point temperature plus a programmable differentialtemperature. Refrigerant flows to the electronic expansion valve(s) 8, 9which will be positioned to regulate refrigerant flow 2 and superheatvalues as needed to maintain air and water temperature set points. Theelectronic EPR valve 23, also referred to as a freeze protection valve,will be positioned by the PLC 29 such that the temperature of therefrigerant flowing through the liquid cooling section of the evaporatorcoil is always held above the freezing temperature of that liquid(programmable feature).

A distinguishing feature of the water cooling evaporator section is theuse of coaxial tubes. As illustrated in FIG. 3, the innermost tube 32 ofcoaxial tube 30 houses the flow of the process cooling liquid, such aswater, the outer tube 31 houses the refrigerant flow and the entireassembly is in the process cooling airstream. Heat energy issimultaneously transferred from both the air and the water into therefrigerant. The hot return process water may be insulted from thecooling air by the refrigerant “jacket” surrounding evaporator coil 10,as shown. The liquid cooling section 13 has a dedicated electronicexpansion valve that modulates flow to maintain the superheat at the setpoint.

Air cooled by the air cooling section 11, also referred to as an airevaporator coil, is distributed to the space to be cooled by a number ofelectronically commutated backward inclined centrifugal fans, as anexample. The rotational speed of the fans, and therefore the volumetricflow rate of the air, may be a programmable feature. The liquid cooledin the liquid cooling section of the evaporator, also referred to as aliquid cooling section, is distributed to a secondary liquid coolingsystem via a centrifugal pump(s), for example.

The condenser section 3 may be one of two basic models:

-   1) Air cooled condenser with head pressure controlled by one of the    following:    -   a. Variable fan speed control    -   b. Flooded head pressure control    -   c. Combination of both a. and b.-   2) Liquid cooled condenser    -   a. Plate fin heat exchanger with head pressure control valve    -   b. Coaxial heat exchange with head pressure control valve

The PLC 29 will provide all controls, safeties, alarms, and trendingfunctions of the system.

FIG. 2 illustrates a combined air and water cooling evaporator coil 10,in accordance with certain embodiments of the present invention. Thereare one or more air cooling distributors and one or more water coolingdistributors as shown. Further to FIG. 2, FIG. 5 illustrates exampleconstruction of the dual air and liquid evaporator, in accordance withvarious embodiments. In this particular embodiment, it can be seen inthe front view that the air cooling section 11 can be housed in an aircooling coil section of a direct expansion (DX) air conditioning unitwhile the liquid/water cooling section 13 is disposed in the barrelsection of a water cooling coil/chilller.

As shown in FIG. 3, refrigerant flows through the outer tube 32, whileprocess water flows through the inner tube 34 of a coaxial tube, forexample. Process air surrounds the coaxial tube. The combined air andwater cooling evaporator coil has an air cooling section and a watercooling section, as shown in FIG. 3.

The dual evaporators are housed in a common frame that contains the aircooling section 11 of the evaporator coil and the water cooling section13 of the evaporator coil. Details of the evaporator design are shown inFIG. 2 and FIG. 3. Both sections of the evaporator coil are fed avolatile refrigerant that changes phase in the evaporator to remove heatenergy from the air section (11) and the air and the water in the watercooling section 13. In the water cooling section 13 of the evaporatorthe refrigerant flows around the inner tube 32 of the coaxial tube 30while the process liquid, which may be process water, a glycol mixture,or solution, flows through the inside tube, as shown in FIG. 3. Thecoaxial tube 30 is surrounded by air flow that is generated by theevaporator fan 24. Because the refrigerant absorbs heat energy andbecomes a saturated vapor in the evaporator coil, its pressure, andtherefore its temperature, may be controlled by use of an electronicexpansion valve (EEV), one EEV 8 is dedicated to the air cooling sectionand one EEV 9 is dedicated to the liquid cooling section. Therefrigerant temperature in the water cooling section 13 is maintainedbelow the surrounding air temperature and the process water temperatureto insure heat energy flows into the refrigerant from both the waterflowing in the tubes and the air flowing over the evaporator coil. Inthe air cooled section 11 of the evaporator coil the refrigerant flow iscontrolled by the EEV dedicated to that section 8 to control supply airtemperature which is monitored by remote temperature sensor 28;likewise, in the water cooled section EEV 9 controls the leaving(supply) water temperature. The EEVs are controlled by a systemcontroller, such as a programmable logic controller (PLC), like PLC 29,microprocessor, or the like, that receives control inputs fromrefrigerant pressure transducers 12, 26 and refrigerant temperaturesensors 14, 27. Sensors 12, 14 provide inputs to the PLC to control theEEV 8 for the air cooling section and sensors 26, 27 provide inputs tothe PLC to control the EEV 9 for the water cooling section. Thesecontrol inputs to a PLC generate a control response to maintain someuser selectable amount of superheat in the refrigerant to prevent liquid“slugging” of the compressor(s) 1.

The compressor(s) 1 provide the mass flow rate of refrigerant throughthe apparatus. The compressors could be one or more of the followingtypes: scroll, reciprocating, semi hermetic, screw, tandem, digital,electronically commutated, of variable frequency speed controlled. Thecompressor(s) 1 are controlled by the PLC 29 to ensure sufficientcooling of the air and water.

The condenser 3 may be an air, water, or glycol cooled condenser, suchas that illustrated in FIG. 1. The condenser transfers the heat energyabsorbed into the refrigerants to the cooling medium (air, water, orglycol) so that that heat energy can be transferred to the environment.Condensing temperature is controlled by a head pressure control valve 4for a water or glycol cooled condenser and is controlled by fan speed orfan cycling for air cooled condensers. A refrigerant receiver 5 islocated downstream from the condenser 3, the receiver 5 stores excessrefrigerant, allows for expansion and contraction of the refrigerantduring transient conditions and insures that the EEVs 8, 9 have 100% ,or close to 100%, liquid refrigerant fed to them. This is important forproper EEV operation. Also, refrigerant receiver 5 may have a pressurerelief valve as shown. Prior to the refrigerant flowing to the EEVs itpasses through refrigerant drier strainer 6 to remove water from therefrigerant and strain out any contaminates such as brazing debris. Arefrigerants site glass 7 aids in refrigerant charging and indicates thepresence of water in the refrigerant.

After the refrigerant flows through the air and water cooling sectionsof the evaporator it flows through the electronic evaporator pressureregulator (EEPR) valve 23. The EEPR valve is controlled by the PLC 29 toprovide two distinct functions:

-   Provide freeze protection of the liquid/water cooling section 13 of    the evaporator coil 10. This is needed to ensure that the coaxial    tubes 30 are not damaged by water freezing in the center of the    tube. This is accomplished by monitoring supply water temperature    provided by the temperature sensor 15 as well as a refrigerant    saturation temperature and pressure provided to the PLC 29 by    pressure sensor 26 and temperature sensor 27. By maintaining the    refrigerant pressure above the freezing point of the water or other    liquid, the liquid/water cooling section will be protected against    freezing damage.-   Stabilize common compressor suction line pressures. The refrigerant    flowing through the two sections of the evaporator will at times be    at very different portions of the refrigerant saturation curve. The    common suction line serves as a direct contact heat exchanger where    the two parallel refrigerant streams mix. The PLC 29 monitors the    temperature sensor 14 and pressure sensor 12 and provides a control    signal to constantly adjust the EEPR valve position to maintain    refrigerant conditions within acceptable range. This adjustment may    be performed constantly, close to real time, or it may be performed    periodically.

The water or liquid supply system feeds water cooled equipment wherethat heat energy is absorbed by the liquid and returned to the liquidcooled section 13 of the evaporator coil 10 where that heat istransferred into the refrigerant. Liquid flow through the apparatus isprovided by the use of pumps 16, 20. The pumps can be of the centrifugalor the positive displacement variety. They could be constant speed orspeed controlled pumps. They may be single pumps (16) or multiple pumps16, 20 provided for redundancy. The pumps are typically provided withcheck valves to prevent backflow through an idle pump and isolation orshut-off valves 17 to facilitate repair and maintenance. A strainer 21is supplied to remove any particles that may be in the liquid/water linedue to construction or the formation of corrosion products. The supplyand return lines have temperatures sensors 15, 22, respectively, thatprovide temperature information to the PLC 29 to control pumps 16, 20,compressors 1, and EEVs 8, 9, etc.

The dual air and liquid evaporator is particularly advantageous in heatremoval of liquid cooled servers, such as may be used in liquid cooledserver racks and/or micro data centers 25, as illustrated in FIG. 4. Inthe drawing, within the dashed box, a number of micro cooled servers inline with auto shut off valves are shown. Further to FIG. 4, FIGS. 6 and7 illustrate an example rendering in which the dual air and liquidevaporator is housed in a micro data center. These drawings show thecabinet doors of a micro data center in both closed and openconfigurations.

In accordance with the various embodiments presented herein, the dualair and liquid evaporator may be advantageously used to cool suchconfigurations having cool liquid cooled servers. Servers can be liquidcooled to support much higher watt densities then can be cooled with airalone. Liquid cooling also requires just a fraction of the power thattraditional server air cooling requires. The vast majority of the heatload within a contemporary server is generated by the central processingunit, graphic processing unit, random access memory dual inline memorymodules (RAM DIMM), and voltage regulators. These components alone canrepresent between 70% and 80% of the heat generated by the computerserver. Small liquid cooled heat exchangers, including, for example,water cooled heat exchangers and water cooled jackets, can be attacheddirectly to these server components and the liquid cooled by the dualair and liquid evaporator can be used to remove this heat energy so thatit can be rejected to the outside through the dual air and liquidevaporator's condenser, as previously explained. The liquid is fed backto the dual air and liquid evaporator to be re-cooled in the liquidcooling section of the dual air and liquid evaporator to repeat thecycle.

Even though the vast majority of the heat energy can be removed by thecooling liquid provided by the liquid cooling section, there are stillcomponents on the server mother board, notably, that produce heat butare too small to have individual liquid/water cooled heat exchangers orliquid/water cooled jackets attached directly to them. Nonetheless,these components, such as resistors, capacitors, wires, and soldertraces need to have the heat they produce removed by the use of aircooling. The air that is cooled in the air cooling section of the dualair and liquid evaporator is directed by cabinetry or ducting to supplythis cooling air to the servers. The air, once heated by the servers, isreturned to the dual air and liquid evaporator by ducting or cabinetryto be re-cooled and the cooling system is started again. The air coolingsection of the dual air and liquid evaporator may additionally serve asa dehumidifier to remove excess moisture from the air circulated throughthe computer server. Excess moisture in the air can lead to advancedcorrosion that can potentially destroy the server. The cold refrigeranttubes in the air cooling section of the dual air and liquid evaporatorwill strip the excessive moisture by absorbing the latent heat ofvaporization from the liquid/water vapor in the air. This condensedliquid may flow downward into a drain pan under the evaporator coil, forexample, where it can be removed via gravity or a condensate pump.

System Controls

The dual air and liquid evaporator or evaporator system is equipped witha programmable logic controller (PLC) 29 with software designed tooperate components such as the compressor(s), speed drives, fans, EEVs,EEPRs, and pumps discussed above.

Although it ultimately controls supply liquid/water temperature andsupply air temperatures, the PLC 29 may also monitor and control allinternal and external control functions in accordance with certainembodiments. The parameters of the system and dual air and liquidevaporator that are controlled and/or monitored by the PLC may includetemperature and humidity set points, multiple stages of cooling anddehumidification, input power, delays, run time history, and alarmstatus.

The display of the PLC indicates the actual temperature, relativehumidity, dew point, and all current active functions such as heat,cool, dehumidification and humidification, set points, alarms, andparameter modifications using a series of menus.

Cooling Controls

The PLC 29 cycles compressor(s) 1 on and off for capacity control whenthe controller determines that each stage of cooling is called for. Ifthe compressors are variable speed models then the PLC adjustscompressor rotation speed to match the required air and liquid/watercooling mode. The stages of cooling are turned on based upon thecontroller's cooling response to temperature and humidity inputs fromthe air and liquid sensors. Each cooling stage will turn on, following atime delay, once the programmed “Cooling Stage Enable” set point valuefor that stage has been reached. The compressor(s) are turned off whenthe controller set points for each stage is satisfied.

The PLC is equipped with analog input positions for monitoringtemperature and humidity sensor(s) for automatic operation of the airconditioner. Sensor(s) may be duct or cabinet mounted to monitor returnair and supply liquid conditions and/or located to monitor the supply orroom/cabinet/server air conditions for the controller to determine thedemand for cooling and dehumidifying against the control set points. Thecontroller determines the appropriate response output signal(s) indirect proportion to the return air sensor input signal(s) to operatethe A/C system modes.

Control of the Evaporator Fan

The PLC is configured to control the evaporator fan 24 speed from 100%to a minimum setting of the total system airflow volume, for example.Minimum, maximum, and dehumidification fan speed settings may be useradjustable locally at the PLC terminal. If the evaporator fan motor is aconstant speed device than in certain embodiments the fan will run at100% fan speed at all times. If it is a variable speed motor the fan maydecrease its rotational speed during periods of low air cooling loadand/or dehumidification load.

Dehumidifying Controls

When dehumidification is called for the controller will operate thecompressor(s) 1 at full output to strip moisture from the air. Thesystem remains in the cooling mode until the actual relative humidity(or dew point) reaches the humidity (or dew point) set point plus thedehumidification cut-off offset or until the dehumidification minimumtemperature is reached.

The controller, PLC or otherwise, may be configured for temperature andrelative humidity or dew point control for dehumidification andhumidification functions. When enabled for traditional relative humiditycontrol, the controller may continuously monitor the selected humiditycontrol sensors (outdoor air or return air) to determine when toactivate the humidification or dehumidification modes.

When enabled for dew point control, the controller logically examinesthe coupling of temperature and relative humidity (dew point) anddetermines the proper control of cooling and dehumidification to movethe actual conditions to within the boundaries of thetemperature/humidity set points as they would appear on a psychrometricchart (see below). It may avoid scenarios where the A/C unit might bothcool and humidify the supply air when cooling alone will achieve thedesired result.

Summary of Methodologies Described Herein

Referring now to FIG. 8, a flow 800 illustrates a methodology forsimultaneously providing air and fluid cooling by a dual air and liquidevaporator. In block 810, a refrigerant is provided to a dual air andliquid evaporator that becomes a saturated vapor in air and liquidcooling sections of the dual air and liquid evaporator. Refrigerant maybe provided simultaneously to the air and liquid cooling sections. Thephase of the refrigerant in the air cooling section is controlled togenerate cooled supply air by the air cooling section in block 820,while the phase of the refrigerant is controlled in the liquid coolingsection to generate cooling supply liquid by the liquid cooling sectionat block 830. The generated supply air and the generated supply liquidcan then be provided to one or more devices having components cooled bythe received supply liquid and components cooled by the received supplyair at block 840.

Further method actions that may be taken in accordance with variousembodiments, described at length above, include:

-   transferring heat energy absorbed by the refrigerant in the air    and/or liquid cooling sections to the environment outside the dual    air and liquid evaporator.-   controlling the temperature of the refrigerant in the air cooling    section to control the temperature of the generated supply air and    controlling the temperature of the refrigerant in the liquid cooling    section to control the temperature of the generated cooling supply    liquid.-   maintaining the temperature of the refrigerant in the liquid cooling    section below the temperature of air surrounding the liquid cooling    section and below the temperature of process liquid flowing in the    liquid cooling section. This may be performed by a control element,    such as valve 9 used to control liquid cooling section 13.-   controlling a first control element that controls the temperature of    the refrigerant in the air cooling section responsive to pressure or    temperature measurements of the refrigerant in the air cooling    section, and controlling a second control element that controls the    temperature of the refrigerant in the liquid cooling section    responsive to pressure or temperature measurements of the    refrigerant in the liquid cooling section. As described PLC 29 may    control 8 to control the temperature of the refrigerant in air    cooling section 11 responsive to measurements taken by sensors 12,    14, while PLC 29 may control 9 to control the temperature of the    refrigerant in liquid cooling section 13 response to measurements    taken by sensors 26, 27. Further the heat level of the refrigerant    can be maintained responsive to temperature and/or pressure    measurements of the refrigerant in the air and/or liquid cooling    sections; compressors 1, which controls the mass flow rate of the    refrigerant, can be controlled by PLC 29 responsive to such    measurements. The level of heat of the refrigerant may be selected    by a user or programmed, for example.-   removing water and/or contaminants from the refrigerant before    providing refrigerant to the dual air and liquid evaporator.-   sensing the temperature of the generated supply liquid; measuring    the refrigerant saturation temperature and/or pressure of the    refrigerant in the liquid cooling section; and responsive to one or    both of the temperature of the supply liquid and the refrigerant    saturation temperature and/or pressure, maintaining pressure of the    refrigerant in the liquid cooling section above a threshold. Where    the liquid cooling section is a water cooling section, the    refrigerant pressure in the water cooling section is maintained    above the freezing point of water.-   providing the generated supply air and the generated supply liquid    to devices, such as servers of a micro data center or in a server    rack, having components cooled by the received supply liquid and    components cooled by the received supply air. Again, the supply    liquid can be used to cool central processing units (CPUs), graphic    processing units, random access memory (RAM), random access memory    dual inline memory modules (RAM DIMM), and voltage regulators while    the supply air can be used to cool resistors, capacitors, wires, and    solder traces. Liquid from the devices can be returned to the dual    air and liquid evaporator via a return line and excess moisture can    be removed by the air cooling section and contaminants can be    removed from return liquid prior to be looped back to the dual air    and liquid evaporator.

More specifically, reference is made to the block diagram of FIG. 9 iswhich a process of dual air and water cooling within the system, inaccordance with various representative embodiments, is shown. Thefollowing description uses the reference numbers of previous figures.

Refrigerant Circuits:

Call for Cooling

Air and water sensor outputs 15, 22, 28 are monitored by theprogrammable logic controller PLC 29. When the programmable temperatureset point is reached for water and/or air the first compressor 1 iscycled on. The compressor begins the flow of the volatile refrigerantthrough the system. Any additional compressors 1 cycle on when the airor water temperatures reach set point plus the programmable offsettemperature between compressor stages plus a programmable temperaturedead band.

The deferential pressure created by the running compressor 1 forcesliquid refrigerant in the liquid line to flow from the receiver 5through the drier strainer 6 and the sight glass 7 where it is then madeavailable to the air cooling and water cooling electronic expansionvalves 8, 9. The valves throttle open on a signal from the PLC, thealgorithm in the PLC that controls the valves is a series ofproportional integral and derivative (PID) loops that control thefollowing:

-   1. Leaving air temperature-   2. Superheat in the refrigerant in the air cooling section of the    coil-   3. Leaving water temperature-   4. Superheat in the refrigerant in the water cooling section of the    coil

The PLC 29 is programmed to ensure that super heat in either circuitdoes not drop below 5° F. (2.8° C.), for example. The flow is constantlythrottled based on the changing air and water temperatures as well asthe changes in superheat.

Refrigerant leaving the air cooling section electronic expansion valve 8begins to change phase due to the pressure drop across the valve seat. Asaturated vapor/liquid refrigerant mixture then enters the air coolingcoil section where it continues to absorb heat energy from the airflowing over the coil. As the refrigerant absorbs this heat energy itcontinues to change phase converting from a saturated liquid/vapormixture to a super-heated vapor.

Refrigerant leaving the water cooling section electronic expansion valve9 begins to change phase due to the pressure drop across the valve seat.A saturated vapor/liquid refrigerant mixture then enters the watercooling coil section where it continues to absorb heat energy from thewater flowing through the internal tube 32 and air flowing over theouter tube 31. As the refrigerant absorbs this heat energy it continuesto change phase converting from a saturated liquid/vapor mixture to asuper-heated vapor. In addition to the electronic evaporator expansionvalve the electronic evaporator pressure regulator valve actuates asnecessary to keep refrigerant temperature above freezing to ensure thatthe water flowing through the inner tube 32 does not freeze and damagethe evaporator. The electronic evaporator pressure regulator ispositioned by the PLC 29 based on inputs from the temperature andpressure sensors located in the refrigerant piping 26, 27.

The low pressure, low temperature refrigerant exiting the air and watercooling sections of the evaporator is sucked into the compressor 1suction where it is converted to a high pressure high temperature gas.This gas then flows into the air, water, or glycol condenser where itrejects its heat to the air, water, or glycol so that that heat can betransferred to somewhere where it is not objectionable (outdoorstypically).

By this process both air and water are cooled to set point.

If the heat load in the air or water decreases such that cooling is notnecessary as indicated by the air or water sensors 15, 22, 28 the PLC 29will begin cycling off the compressors 1 sequentially to match thecurrent heat load.

Water circuits:

Call for cooling

The PLC sends an enable signal to the primary water pump 16 which startsthe pump. After a programmable time delay the PLC 29 compares the inputfrom temperature sensors 15, 22 to ensure that a temperature deltaexists (verifying that there is water flow prior to energizing acompressor). The water flows to the heat load heat exchanger (typicalheat load represented by 25). The heat energy is transferred into waterfrom the heat source. The water then flows through a fine mesh strainerto ensure that no significant particulate that may be trapped in thewater piping may enter the water cooling section of the evaporator. Thestrainer can be cleaned while the system is in operation. The heatedwater then enters the inner tubes 32 of the water cooling section 13 ofthe evaporator coil where it rejects the heat energy that it hasabsorbed into the refrigerant flowing though the outer tubes 31. Thecooled water now flows into the suction of the pump and the cycle beginsagain.

Standby pump:

If water temperatures sensors indicate that the water temperature isabove set point but there is not the set point delta between thetemperatures as indicated to the PLC 29 by sensors 15, 22 this willregister as a primary pump failure and the standby pump will beactivated and primary pump turned off

The above systems, devices, methods, processes, and the like may berealized in hardware, software, or any combination of these suitable fora particular application. The hardware, including the PLC, may include ageneral-purpose computer and/or dedicated computing device. Thisincludes realization in one or more microprocessors, microcontrollers,embedded microcontrollers, programmable digital signal processors orother programmable devices or processing circuitry, along with internaland/or external memory. This may also, or instead, include one or moreapplication specific integrated circuits, programmable gate arrays,programmable array logic components, or any other device or devices thatmay be configured to process electronic signals. It will further beappreciated that a realization of the processes or devices describedabove may include computer-executable code created using a structuredprogramming language such as C, an object oriented programming languagesuch as C++, or any other high-level or low-level programming language(including assembly languages, hardware description languages, anddatabase programming languages and technologies) that may be stored,compiled or interpreted to run on one of the above devices, as well asheterogeneous combinations of processors, processor architectures, orcombinations of different hardware and software. In another aspect, themethods may be embodied in systems that perform the steps thereof, andmay be distributed across devices in a number of ways. At the same time,processing may be distributed across devices such as the various systemsdescribed above, or all of the functionality may be integrated into adedicated, standalone device or other hardware. In another aspect, meansfor performing the steps associated with the processes described abovemay include any of the hardware and/or software described above. Allsuch permutations and combinations are intended to fall within the scopeof the present disclosure.

Embodiments disclosed herein may include computer program productscomprising computer-executable code or computer-usable code that, whenexecuting on one or more computing devices, performs any and/or all ofthe steps thereof. The code may be stored in a non-transitory fashion ina computer memory, which may be a memory from which the program executes(such as random access memory associated with a processor), or a storagedevice such as a disk drive, flash memory or any other optical,electromagnetic, magnetic, infrared or other device or combination ofdevices. In another aspect, any of the systems and methods describedabove may be embodied in any suitable transmission or propagation mediumcarrying computer-executable code and/or any inputs or outputs fromsame.

It will be appreciated that the devices, systems, and methods describedabove are set forth by way of example and not of limitation. Absent anexplicit indication to the contrary, the disclosed steps may bemodified, supplemented, omitted, and/or re-ordered without departingfrom the scope of this disclosure. Numerous variations, additions,omissions, and other modifications will be apparent to one of ordinaryskill in the art. In addition, the order or presentation of method stepsin the description and drawings above is not intended to require thisorder of performing the recited steps unless a particular order isexpressly required or otherwise clear from the context.

The method steps of the implementations described herein are intended toinclude any suitable method of causing such method steps to beperformed, consistent with the patentability of the following claims,unless a different meaning is expressly provided or otherwise clear fromthe context. So, for example, performing the step of X includes anysuitable method for causing another party such as a remote user, aremote processing resource (e.g., a server or cloud computer) or amachine to perform the step of X. Similarly, performing steps X, Y, andZ may include any method of directing or controlling any combination ofsuch other individuals or resources to perform steps X, Y, and Z toobtain the benefit of such steps. Thus method steps of theimplementations described herein are intended to include any suitablemethod of causing one or more other parties or entities to perform thesteps, consistent with the patentability of the following claims, unlessa different meaning is expressly provided or otherwise clear from thecontext. Such parties or entities need not be under the direction orcontrol of any other party or entity, and need not be located within aparticular jurisdiction.

It should further be appreciated that the methods above are provided byway of example. Absent an explicit indication to the contrary, thedisclosed steps may be modified, supplemented, omitted, and/orre-ordered without departing from the scope of this disclosure.

It will be appreciated that the methods and systems described above areset forth by way of example and not of limitation. Numerous variations,additions, omissions, and other modifications will be apparent to one ofordinary skill in the art. In addition, the order or presentation ofmethod steps in the description and drawings above is not intended torequire this order of performing the recited steps unless a particularorder is expressly required or otherwise clear from the context. Thus,while particular embodiments have been shown and described, it will beapparent to those skilled in the art that various changes andmodifications in form and details may be made therein without departingfrom the scope of this disclosure and are intended to form a part of thedisclosure as defined by the following claims, which are to beinterpreted in the broadest sense allowable by law.

The various representative embodiments, which have been described indetail herein, have been presented by way of example and not by way oflimitation. It will be understood by those skilled in the art thatvarious changes may be made in the form and details of the describedembodiments resulting in equivalent embodiments that remain within thescope of the appended claims.

What is claimed is: 1.-36. (canceled)
 37. A dual air and liquidevaporator, comprising: an air cooling section configured to receiverefrigerant that changes phase in the air cooling section to remove heatenergy from the air cooling section; and a liquid cooling section inmechanical communication with the air cooling section and configured toreceive refrigerant that changes phase in the liquid cooling section toremove heat energy from the liquid cooling section, where heat transferfrom the refrigerant in the air and liquid cooling sections iscontrolled to generate a cooled supply air by the air cooling sectionand a cooling supply liquid by the liquid cooling section, where the aircooling section and the liquid cooling section are housed in a commonframe.
 38. The evaporator of claim 37, where the refrigerant becomes asaturated vapor in the air and liquid cooling sections having a pressureand a temperature that can be externally controlled.
 39. The evaporatorof claim 37, where the dual air and liquid evaporator is a dual air andliquid evaporator coil further comprising: tubing; and fins inmechanical communication with the tubing, the tubing and fins configuredin an air cooling section operable to receive refrigerant and a liquidcooling section operable to receive refrigerant; where the refrigerantchanges phase in the air cooling section to remove heat energy from theair cooling section, and where the refrigerant changes phase in theliquid cooling section to remove heat energy from the liquid coolingsection.
 40. The evaporator of claim 39, further comprising coppertubing with aluminum or copper fins.
 41. The evaporator of claim 39, thetubing being coaxial tubing having an inner tube and an outer tube,where in the liquid cooling section, process liquid flows through theinner tube and the refrigerant flows around the inner tube in the outertube.
 42. (canceled)
 43. The evaporator of claim 37, where thetemperature of the refrigerant in the liquid cooling section ismaintained below the temperature of air surrounding the liquid coolingsection and below the temperature of process liquid flowing in theliquid cooling section by a first control device coupled to the dual airand liquid evaporator, and where the temperature of the refrigerant inthe air cooling section is maintained below the temperature of airsurrounding the air cooling section by a second control device coupledto the dual air and liquid evaporator.
 44. The evaporator of claim 37,where the air cooling section and the liquid cooling section are adaptedto receive the refrigerant at the same time.
 45. The evaporator of claim37, where the air cooling section removes excess moisture from airprovided to the air cooling section via a return line. 46.-65.(canceled)
 66. The evaporator of claim 43, where the first controldevice is a first control valve coupled to and in communication with aninput of the air cooling section, where the first control valve controlstemperature of the refrigerant in the air cooling section to control thetemperature of supply air generated by the air cooling section, andwhere the second control device is a second control valve coupled to andin communication with an input of the liquid cooling section, where thesecond control valve controls temperature of the refrigerant in theliquid cooling section to control the temperature of supply liquidgenerated by the liquid cooling section.
 67. The evaporator of claim 66,where the first control valve and the second control valve areelectronic expansion valves.
 68. A dual air and liquid evaporator,comprising: an air cooling section configured to receive refrigerantthat changes phase in the air cooling section to remove heat energy fromthe air cooling section; and a liquid cooling section in mechanicalcommunication with the air cooling section and configured to receiverefrigerant that changes phase in the liquid cooling section to removeheat energy from the liquid cooling section, heat transfer from therefrigerant in the air and liquid cooling sections is controlled togenerate a cooled supply air by the air cooling section and a coolingsupply liquid by the liquid cooling section, the air cooling section andthe liquid cooling section configured to receive the refrigerant at thesame time.
 69. The evaporator of claim 68, where the refrigerant becomesa saturated vapor in the air and liquid cooling sections having apressure and a temperature that can be externally controlled.
 70. Theevaporator of claim 68, where the dual air and liquid evaporator is adual air and liquid evaporator coil further comprising: tubing; and finsin mechanical communication with the tubing, the tubing and finsconfigured in an air cooling section operable to receive refrigerant anda liquid cooling section operable to receive refrigerant; where therefrigerant changes phase in the air cooling section to remove heatenergy from the air cooling section and where the refrigerant changesphase in the liquid cooling section to remove heat energy from theliquid cooling section.
 71. The evaporator of claim 70, furthercomprising copper tubing with aluminum or copper fins.
 72. Theevaporator of claim 70, the tubing being coaxial tubing having an innertube and an outer tube, where in the liquid cooling section, processliquid flows through the inner tube and the refrigerant flows around theinner tube in the outer tube.
 73. The evaporator of claim 68, where theair and liquid cooling sections are housed in a common frame.
 74. Theevaporator of claim 68, where the temperature of the refrigerant in theliquid cooling section is maintained below the temperature of airsurrounding the liquid cooling section and below the temperature ofprocess liquid flowing in the liquid cooling section by a first controldevice coupled to the dual air and liquid evaporator, and where thetemperature of the refrigerant in the air cooling section is maintainedbelow the temperature of air surrounding the air cooling section by asecond control device coupled to the dual air and liquid evaporator. 75.The evaporator of claim 68, where the first control device is a firstcontrol valve coupled to and in communication with an input of the aircooling section, where the first control valve controls temperature ofthe refrigerant in the air cooling section to control the temperature ofsupply air generated by the air cooling section, and where the secondcontrol device is a second control valve coupled to and in communicationwith an input of the liquid cooling section, where the second controlvalve controls temperature of the refrigerant in the liquid coolingsection to control the temperature of supply liquid generated by theliquid cooling section.
 76. The evaporator of claim 75, where the firstcontrol valve and the second control valve are electronic expansionvalves.
 77. The evaporator of claim 68, where the air cooling sectionremoves excess moisture from air provided to the air cooling section viaa return line.
 78. A dual air and liquid evaporator, comprising: an aircooling section configured to receive refrigerant that changes phase inthe air cooling section to remove heat energy from the air coolingsection; a liquid cooling section in mechanical communication with theair cooling section and configured to receive refrigerant that changesphase in the liquid cooling section to remove heat energy from theliquid cooling section, where heat transfer from the refrigerant in theair and liquid cooling sections is controlled to generate a cooledsupply air by the air cooling section and a cooling supply liquid by theliquid cooling section, where the temperature of the refrigerant in theliquid cooling section is maintained below the temperature of airsurrounding the liquid cooling section and below the temperature ofprocess liquid flowing in the liquid cooling section by a first controldevice coupled to the dual air and liquid evaporator, and where thetemperature of the refrigerant in the air cooling section is maintainedbelow the temperature of air surrounding the air cooling section by asecond control device coupled to the dual air and liquid evaporator,where the first control device and the second control device areelectronic expansion valves.